CFD modeling of soot induced radiation in the exhaust plume of rocket engines

Abstract

This paper presents a computational methodology to quantify plume radiation caused by soot particles in rocket exhaust plumes. A Photon-Monte-Carlo-Method is used to solve the radiative transfer equation. This approach accounts for selfabsorption in the exhaust gas which is significant as the plume is close to the optically thick limit for full scale launcher configurations. The radiative properties such as the absorption coefficient (inverse mean free path of the photons) and the emissivity (emitted radiative power per volume and direction) are derived from estimates of the soot mass fraction and particle size. The plume shape and thermodynamic properties are taken from classical CFD analyses. The method is calibrated and assessed based on available flight data for a kerosenefueled rocket engine at different altitudes. Strong agreement with flight data was achieved by using estimates for soot properties which are consistent with the current literature.